Period = (1) / (frequency)
Period = (1) / (200 per second) = 0.005 second = 5 milliseconds
Yes it is. Uh huh, uh huh, shore enuff. Mmm hmm. Yeah yeah yeah. Yah Mon ! Indubitably.
Answer:
(a) A = m/s^3, B = m/s.
(b) dx/dt = m/s.
Explanation:
(a)

Therefore, the dimension of A is m/s^3, and of B is m/s in order to satisfy the above equation.
(b) 
This makes sense, because the position function has a unit of 'm'. The derivative of the position function is velocity, and its unit is m/s.